Packing



i positions.

cal action.

UNITED sTATa s PATENT 4OFFICE.

zaasos PACKING Harry B. Denman, Detroit, Mich., assigner to DetroitGasket 8a Manufacturing Company,

' "Detroit, Mich., a corporation o! Application December 26, 1941,Serial 'Nm-124,513

1 claim. (ci. ,zas-s4) 'This inventionrelates topacking generally and'more particularly to a materialmade up oil layers Y of paper into athickness oi the o rder oi thin paper board which is highly suitableforgasketing purposes in connection with automotive and airplane uses.

According, to the invention, paper layers which A are incompressible andalso inextensible are,

formed into a flexible, resilient laminated'struclture byinterposingbetweenthe layers a nlm of. "resilient material Vpreferablyof less thickness than the paper. This nlm not only bonds the layerstogether but more important, imparts substantial and permanentresiliency to the built-up product as a whole. I particular importance,the resilient built-up product isinextensible underV high sealingcompression, i. e., does.V not a thickness of the order of .005" and areformedy of various furnishes. In some instances, the laysqueee out orilow when clamped between the sealing flanges of a joint. f

The principal object of the invention is topravide a ilexiblelaminatedgasket formed of thin j' but inextensible and incompressible paperlayers and possessed of permanent properties of resilseal. 'Ihat is tosay, the gasket of the present.

invention has the resilient film interposed be- Y tween and protectedbythe paper layers. This f i's a marked improvement because'gaskets madefrom this packing material do not solely depend for their sealingeiiiciency upon the provision of surface coatings which latter sometimesdeteriorate in storage or nder compression due to Vand Ihave shown acircular or ring gasket sole by way ot example.

Referring te Figure 2, the peper layers u have ers i I may be made froma furnish in which is incorporated phenol formaldehyde resin. ureaformaldehyde resin or other synthetic resinsLor the paper may beimpregnated with such resins. .The presence of synthetic resins does notchem` ically change the paper but does impart thereto'.

the desirable characteristics of strength and inextensibility Withoutobjectionably impairing flexibility. "At the same time, such resins willbe vresistant'to and render the paper resistant to water, oils, solventsand elevated or reduced temperatures, i. e., resistantto ,such chemicalaction vand temperature conditions as the gasket will encounter in use.In some cases, the paper layers may be of vulcanizedfibre either of thezinc chloride or sulphuric acid types. The paper, as

will be appreciated, is incompressible.

I have foundthat thin iiexible layers of paper A characterized byinextensibility under compresgasket structure'of the character describedwhich l abrasion or the effects of temperature and -chemi- Referring tthe accompanying drawing: Figure 1 is a plan viewillustrating one form`of gasket, and .A Figure 2 is asectional view on the line 2--2 ofFigure 1. y

The gasket I0 shown in Figure 1 may takeany other form necessary toaducetight seal 65 -as well understood in the art for aiding informvsion but having little lor no compressibility can be laminated intoa permanently resilient inex- -tensible gasket. Referring to Figure 2,the packing' is formed as a built-up structure vhaving a thickness ofthe order of thin paperboard by interposing between the paper layers afilm of resil- 'ient material l2. This material binds the paper layerstogether and imparts permanent resiliency and exibility to the-laminatedstructure as a Whole. As` shown, theresilient films are preferably ofless thickness 'than the paper, namely, of the -order of .0015". Abuilt-up packing of this character, besides having permanent resiliencehas the further limportant advantage of being inextensible,.i. e., thepacking does not squeeze or... now out between' thejoint surfaces underhigh i sealing compression. l

The resilient material I2 will have resistance to water, oils 4andsolvents as well ashigh and re-E duced temperatures according to therequirements for-which the packing is to be used and in some casesmay-be thermosetting. Thus, the resilient lm may be made of Neoprene,Thiokol,"` rubberor rubber'latex or cements including the saine,cellulose acetate. resins such as vinyl acetate and iiexible glues.

similar to the material I2 ora different material ing a tight sealbetween the gasket surfaces and the surfaces of the flanges of thejoint.

In making the gasket, the paper layers may be coated inv any suitablemanner with a film of the adhesive, 'resilient material in spreadableform,

preferably as a solution. Brushing or spraying ture i. e., the layersare subjected to sufficient f pressure to produce a substantiallyhomogeneous structure. In some cases, heat is employed in addition tothe pressure for driving off the solvent and in the case ofthermosetting materials, for setting the same. From the laminated sheetor strip of packing so produced, gaskets l of various shapes and sizesmay be readily stamped.

While I have illustrated in the drawing a packing having three paperlayers, it is to be understood that a packing having from two paperlayers up to an indefinite number of such layers may be formed dependingupon the gasketing conditions which are to be met.

The sheets or strips of laminated packing as well as the gaskets formedtherefrom have an enhanced life both in storage and under compressionbecause the intermediate resilient films I 2 are always protected by thepaper -layers.

' Notwithstanding that the surface films i 3 may deteriorate in storageor lose their efliciency due` purpose, since a permanent resiliency isimparted,`

by the interposed and constantly protected resilient films l2.

Gaskets made in accordance .with the present invention are highly usefulto take care of seal-l ing requirements demanding a' high degree.of

precision because the packing is-not only resistant to high externalpressures such as bolt pressures but high internal pressures occasionedby lthe presence of water or oil as well. Moreover.

the packing can be drawn down to reliably meet v the most v"delicate orcritical sealing conditions.

In other words, the packing formed as described herein is a highlycompressed, resilient, laminated and stable structure having a thicknessof the order of thin paperboard which will meet the most exactingrequirements of the automotive and airplane industry.

It is a significant feature of this invention that the intermediatefilms I2. are formed from a material of such a character and which ispresent. in such amount that it does not exude from between the paperlayers under the forming' pressure or under the sealing pressure towhich the gasket is subjected in use. That is to say, the,-,.sealingmaterial cooperates with the inextensible layers to the end that it iseiective to promote inextensibility while at the same time impartflexibility and permanent compressibility. The resilient films l2 alsoact to protect the paper layers against chemical action and temperatureconditions' and do not swell or deteriorate in the presence of theseinfluences.

I claim:

Flexible packing being a highly compressed laminated flexible structurehaving a thickness of the order of thin paper-board comprising layers offlexible substantially inextensible and incompressible paper, and layersof resilient, flexible, compressible, adhesive material interposedbetween the paper layers and of less thickness than the paper layers,said layers being subjected to suflicient pressure to produce a.substantially homogeneous structure, said resilient, compressible,adhesive layers binding the paper layers together and rendering thestructure as a whole permanently resilient and compressible under boltpressure without rendering the built-up structure extensible so that itdoes not squeeze out under internal and external pressures, theresilient adhesive being present in amount as not to exude under highsealing pressure or destroy the exibility of the built-up structure,said paper layers protecting the resilient binding layers, whereby theresiliency and inextensibility ofthe composite structure is permanentlyassured in the presence of high pressures, water, oils, solvents andtemperature variations and is not dependent on surface coatings.

HARRY B. DENMAN.

